CN111852457A - Device and method for identifying karst pore passage of fracture-cavity type oil reservoir - Google Patents
Device and method for identifying karst pore passage of fracture-cavity type oil reservoir Download PDFInfo
- Publication number
- CN111852457A CN111852457A CN202010884819.4A CN202010884819A CN111852457A CN 111852457 A CN111852457 A CN 111852457A CN 202010884819 A CN202010884819 A CN 202010884819A CN 111852457 A CN111852457 A CN 111852457A
- Authority
- CN
- China
- Prior art keywords
- karst
- test
- pressure
- well
- degree
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000011148 porous material Substances 0.000 title claims abstract description 109
- 238000000034 method Methods 0.000 title claims abstract description 33
- 238000012360 testing method Methods 0.000 claims abstract description 192
- 230000004044 response Effects 0.000 claims abstract description 77
- 230000010363 phase shift Effects 0.000 claims abstract description 49
- 238000001914 filtration Methods 0.000 claims abstract description 8
- 230000000737 periodic effect Effects 0.000 claims description 57
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 41
- 238000005086 pumping Methods 0.000 claims description 34
- 239000003129 oil well Substances 0.000 claims description 30
- 238000003860 storage Methods 0.000 claims description 22
- 238000004804 winding Methods 0.000 claims description 21
- 239000011159 matrix material Substances 0.000 claims description 20
- 238000002347 injection Methods 0.000 claims description 19
- 239000007924 injection Substances 0.000 claims description 19
- 238000004364 calculation method Methods 0.000 claims description 17
- 238000010586 diagram Methods 0.000 claims description 12
- 238000005315 distribution function Methods 0.000 claims description 5
- 230000009471 action Effects 0.000 claims description 4
- 230000005484 gravity Effects 0.000 claims description 4
- 230000009467 reduction Effects 0.000 claims description 4
- 102000010637 Aquaporins Human genes 0.000 claims description 3
- 238000012935 Averaging Methods 0.000 claims description 3
- 238000012545 processing Methods 0.000 claims description 3
- 239000000758 substrate Substances 0.000 claims description 3
- 238000004891 communication Methods 0.000 abstract description 3
- 238000004458 analytical method Methods 0.000 description 8
- 238000004088 simulation Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 5
- 239000000243 solution Substances 0.000 description 4
- 238000011161 development Methods 0.000 description 3
- 238000009434 installation Methods 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 239000000700 radioactive tracer Substances 0.000 description 2
- 238000009933 burial Methods 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000638 stimulation Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Remote Sensing (AREA)
- Geophysics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
The invention discloses a device and a method for identifying karst pore canals of a fracture-cavity type oil reservoir, wherein the device comprises a power device, a pressure generation device, a filtering device, a processor, a controller and a plurality of pressure testers. According to the invention, the communication degree of the plurality of test wells and the pressure source well is judged according to the amplitude response degree and the phase shift degree of each test well, so that whether the area where the test wells are located is in the karst pore passage area is judged.
Description
Technical Field
The invention relates to the technical field of oil and gas field development, in particular to a device and a method for identifying karst ducts of a fracture-cavity type oil reservoir.
Background
According to statistics, more than 30% of the global carbonate reservoirs are fracture-cavity type reservoirs, wherein the fracture-cavity type reservoirs in oil and gas resources of the western carbonate reservoirs in China account for about 2/3, and the fracture-cavity type reservoirs are important fields for increasing, storing and raising the yield of the petroleum in China. The fracture-cavity oil reservoir mainly comprises karst pore passages and fractures formed by karst and tectonic movement, wherein the karst pore passages are distributed in a discrete shape and are main storage spaces, and the fractures are main flow channels and have the characteristics of deep burial, strong heterogeneity, great development difficulty and the like. When a fracture-cavity type oil reservoir is developed, the most reasonable oil-gas field development scheme needs to be formulated according to the condition of karst pores in the oil reservoir, so that the recovery ratio of the fracture-cavity type oil reservoir is improved, and therefore, the identification of the karst pores in the oil reservoir is a crucial link before the fracture-cavity type oil reservoir is developed.
At present, the karst pore canal is generally identified by representing the hydrodynamic characteristics of the karst pore canal and a fracture aquifer, and the hydrodynamic characteristics of the karst pore canal and the fracture aquifer are generally represented by adopting the following method: tracer tests, slug tests, geophysical studies, and water pumping tests, among others.
The method for identifying the karst pore passage of the fracture-cavity oil reservoir by tracer test, slug test, geophysical research and the like is complicated, has large workload and high cost, causes certain pollution to the stratum, and cannot well meet the field requirement. The water pumping test is used for completing the characterization of the hydrodynamic characteristics of the aquifer by analyzing the hydraulic response of the transmissivity and the light transmittance parameters to the aquifer stimulation. But in practice it is susceptible to noise, and many sources of noise are uncontrollable. To address this challenge, harmonic pumping tests have been proposed as an effective way to characterize hydrodynamic characteristics such that the hydrodynamic signal can be utilized even at low signal amplitudes and noise corruption, which by applying filtering techniques can more easily extract the hydraulic response caused by harmonic excitation of the emitted frequency from the ambient noise. The harmonic pumping test also offers the possibility of avoiding non-linear mechanisms of groundwater flow by controlling the characteristics of the periodic excitation that is currently done by pump-reinjection systems and that requires shut-in during the test, which can affect the production progress.
Disclosure of Invention
In view of the above problems in the prior art, the first technical problem to be solved by the present invention is: the device for identifying the karst pore passage of the fracture-cavity type oil reservoir is low in cost, simple to install and free of well shut-in the using process.
The second technical problem to be solved by the present invention is: the method for identifying the karst pore passage of the fracture-cavity type oil reservoir can greatly improve the accuracy of identifying the fracture-cavity type oil reservoir on the basis of simplicity, practicability and low cost.
In order to solve the first technical problem, the invention adopts the following technical scheme: a device for identifying karst ducts of a fracture-cavity type oil reservoir comprises a power device, a pressure generation device, a filtering device, a processor, a controller and a plurality of pressure testers; the power source is not shown in the figure.
The pressure generating device comprises a connecting rod and a piston plate; the piston plate is of a circular plate structure, the piston plate is horizontally arranged, the connecting rod is vertically arranged above the piston plate, the lower end of the connecting rod is fixedly connected with the center of the piston plate, the piston plate is arranged in the pressure source well, and the piston plate is in sliding fit with the inner wall of the pressure source well.
The power device comprises a power source, a winding roll, a rope and a pulley; the pulley is positioned above the winding roll and the connecting rod, the winding roll and the connecting rod are respectively positioned on two sides of the pulley, one end of the rope is fixed on the winding roll, the other end of the rope upwards rounds the pulley and is fixedly connected with the upper end of the connecting rod, and the power source is used for driving the winding roll to rotate; and the testing ends of the pressure testers are respectively positioned in the testing wells.
The signal output ends of all the pressure testers are respectively connected with the signal input end of the filter device, the signal output end of the filter device is connected with the signal receiving end of the processor, the signal output end of the processor is connected with the signal input end of the controller, and the control signal output end of the controller is connected with the power source.
The device for identifying the karst pore passage of the fracture-cavity type oil reservoir generates a harmonic periodic pressure signal through the up-and-down reciprocating motion of the piston plate, does not need any pumping or injection, is low in cost, pollution-free and simple in installation, does not need to be shut down in the using process, can normally mine an oil well, and avoids influencing the balance and the mining progress of the whole mining system due to the shut-down.
In order to solve the second technical problem, the invention adopts the following technical scheme: a method for identifying karst tunnels of a fractured-vuggy reservoir is characterized in that a test area to be subjected to karst tunnel identification is determined in a fractured-vuggy reservoir area needing to be developed currently, a plurality of oil wells are arranged in the test area, any oil well is selected from the plurality of oil wells in the test area to serve as a pressure source well, and the plurality of oil wells are selected from the plurality of oil wells in the test area to serve as test wells.
The device for identifying the karst pore canal of the fracture-vug reservoir is used for calculating the amplitude response degree and the phase shift degree of each test well in the test area, and whether the test well is in the karst pore canal area or not is judged according to the value interval of the amplitude response degree and the phase shift degree of the test well:
when the phase deviation degree of the test well is less than +100 degrees and the amplitude response degree is greater than 0, a karst pore canal which is communicated with each other is formed between the test well and the pressure source well, and the area where the test well is located in the karst pore canal area.
When the phase deviation degree of the test well is more than or equal to +100 degrees and the amplitude response degree is more than 0, a karst pore canal communicated with the pressure source well is arranged near the test well, and the area where the test well is located is in the karst pore canal area.
When the amplitude response degree of the test well is 0, no karst pore canal which is communicated with the pressure source well exists between the test well and the pressure source well, and no karst pore canal which is communicated with the pressure source well exists nearby the test well, so that the area where the test well is located is not located in the karst pore canal area.
The method for identifying the karst pore canal of the fracture-cavity type oil reservoir has the advantages that the device for identifying the karst pore canal of the fracture-cavity type oil reservoir is low in cost, free of pollution, simple to install and free of well closing, and the current test area can be judged directly according to data measured by the device.
Preferably, the step of calculating the amplitude response degree and the phase shift degree of each test well comprises:
s110: and placing the pressure generating device into a pressure source well, and placing the testing ends of the plurality of pressure testers into a plurality of testing wells respectively.
S120: the processor sends periodic harmonic pressure signals to the controller, the controller controls the power source to drive the winding roll to do circular reciprocating motion according to the periodic harmonic pressure signals, and the piston plate does up-and-down periodic motion under the action of pulling force and self gravity, so that periodic harmonic pressure is generated in the pressure source well.
S130: and each pressure tester transmits a pressure signal which corresponds to the pressure value in the test well and changes along with time to the filtering device, the filtering device performs noise reduction processing on the pressure signal of each test well according to the periodic harmonic pressure signal in the S500, and then the filtering device transmits the noise-reduced pressure signal of each test well to the processor.
S140: and the processor calculates the pressure signal of each test well according to the periodic harmonic pressure signal in the S120 to obtain the amplitude response degree and the phase deviation degree of the pressure signal of each test well.
The device for identifying the karst pore passage of the fracture-cavity oil reservoir has the advantages of low cost, no pollution, simple installation, no need of closing the well, and high accuracy of the amplitude response degree and the phase deviation degree of the measured pressure signal of the test well.
Preferably, the method for determining the value intervals of the phase shift degree and the amplitude response degree for judging whether the test well is in the karst pore passage area comprises the following steps:
the method comprises the following steps of obtaining value intervals of phase shift degree and amplitude response degree for judging whether a test well is in a karst pore passage area or not through a simulated underground periodic water pumping test, and specifically comprises the following steps:
s210: and obtaining a karst region schematic diagram and reservoir parameters of the N real fracture-cavity reservoirs, wherein the reservoir parameters comprise reservoir size, hydraulic conductivity of karst large channels, hydraulic conductivity of karst small channels, water storage coefficient of karst channels, matrix hydraulic conductivity and matrix water storage coefficient.
And S220, establishing a geological model of the fracture-cavity type oil reservoir for simulating the underground periodic pumping test of the karst region by taking the karst region schematic diagram of the real fracture-cavity type oil reservoir and the oil reservoir parameters as conditions.
And S230, setting a buffer area for simulating the underground periodic water pumping test.
S240, selecting a pressure injection point and a plurality of pressure test points from the geological model, and setting the period parameter and the amplitude parameter of the periodic flow signal of the pressure injection point, wherein the pressure injection point and the plurality of pressure test points respectively correspond to the oil wells in the karst region of the real fracture-cavity oil reservoir.
And S250, placing the geological model into a buffer area for simulation to perform an underground periodic water pumping test to obtain the amplitude response degree and the phase deviation degree of each test point.
And S260, analyzing the amplitude response degree and the phase shift degree of each test point, and comparing the amplitude response degree and the phase shift degree with the real condition whether the karst region of the real fracture-vug type oil reservoir is in the karst pore region to obtain a value interval for judging whether the test well is in the phase shift degree and the amplitude response degree of the karst pore region.
S270, repeating the steps S220-S260 to obtain N value intervals for judging the phase deviation degree and the amplitude response degree of the test well in the karst pore canal region, eliminating the value intervals which obviously have calculation errors and are far larger or far smaller than the value intervals in the N value intervals, and averaging the rest value intervals to obtain the value intervals of the phase deviation degree and the amplitude response degree which are finally used for judging whether the test well is in the karst pore canal region.
The amplitude response degree and the phase shift degree of each test well in a plurality of real fracture-cavity type oil reservoir regions are obtained through a plurality of times of simulated underground periodic water pumping tests, the amplitude response degree and the phase shift degree of each test point are analyzed and compared with the real situation that whether the karst region of the real fracture-cavity type oil reservoir is in the karst pore region, and the value intervals of the phase shift degree and the amplitude response degree of judging whether the test well is in the karst pore region are obtained.
Preferably, the geological model comprises governing equations, initial condition equations and boundary condition equations, the governing equations are shown in equations (1-1) and (1-2),
in the formulas (1-1) and (1-2), i is an imaginary unit, and ω represents the frequency of the pumping signal，SmatWater storage coefficient for the substrate, KmatIs the hydraulic conductivity of the matrix, gammaωFor phasors at a given frequency, QmRepresenting the amplitude, Q, of a periodic flow signalmRepresenting the amplitude of a periodic flow signal, (x-x)p) Is a Dirichlet distribution function, SkarIs the water storage coefficient of the karst pore canal,
is a tangent gradient operator in the karst pore canal, KkarIs the hydraulic conductivity of the karst pore canal.
The initial condition formula is shown as (2-1), the boundary condition formula is shown as (2-2),
γω(x,y)＝0(x,y)∈Ωboundary(2-2)，
in the equations (2-1) and (2-2), x represents the abscissa of the model, y represents the ordinate of the model, Ω represents the entire matrix and karst pore canal domain, and Ω representsboundaryRepresenting the domain boundary.
The control equation, the initial condition formula and the boundary condition formula are used for establishing a geological model of the real fracture-cavity type oil deposit, so that the real condition of the oil deposit can be well restored, and the authenticity and reliability of data obtained by a simulation test are ensured.
Preferably, when the buffer is set in S230, an amplitude calculation formula, a phase shift calculation formula and buffer parameters are used, and the buffer parameters include a buffer size, a buffer hydraulic conductivity and a buffer water storage coefficient.
The amplitude calculation formula is shown as (3-1), the phase shift calculation formula is shown as (3-2),
in equations (3-1) and (3-2), M represents the amplitude, x represents the abscissa of the model, y represents the ordinate of the model, Re represents the real part, γωFor the phasor at a given frequency, Im is the imaginary part,
indicating a phase shift.
The buffer area for the simulation test is established by using the amplitude calculation formula and the phase offset calculation formula, so that the phase offset degree and the amplitude response degree of each test point can be calculated more accurately, and the authenticity and the reliability of data obtained by the simulation test are ensured.
Compared with the prior art, the invention has at least the following advantages:
1. according to the device for identifying the karst pore passage of the fracture-cavity type oil reservoir, the harmonic periodic pressure signal is generated through the up-and-down reciprocating motion of the piston plate, any pumping or injection is not needed, the cost is low, no pollution is caused, the installation is simple, the well does not need to be shut down in the using process, the oil well can be normally exploited, and the exploitation progress is prevented from being influenced by the shut-down.
2. The method for identifying the karst pore canal of the fractured-vuggy reservoir has the advantages that the device for identifying the karst pore canal of the fractured-vuggy reservoir is low in cost and simple to install, a well does not need to be shut down, the accuracy of the amplitude response degree and the phase deviation degree of the measured pressure signal of the test well is high, the current test area is judged directly according to the amplitude response degree and the phase deviation degree of the test well, and simplicity and accuracy are realized.
3. According to the method, through a plurality of times of simulated underground periodic water pumping tests, the amplitude response degree and the phase shift degree of each test well in a plurality of real fracture-cavity type oil reservoir regions are obtained, the amplitude response degree and the phase shift degree of each test point are analyzed and compared with the real situation that whether the karst region of the real fracture-cavity type oil reservoir is in the karst pore region or not, the value intervals of the phase shift degree and the amplitude response degree for judging whether the test well is in the karst pore region or not are obtained, the conclusion of the method is obtained based on the tests using real data for a plurality of times, and the method has wide applicability.
Drawings
Fig. 1 is a schematic diagram of the device for identifying karst tunnels of a fracture-cavity reservoir in the invention.
FIG. 2 is a flow chart of a method for identifying karst tunnels for a fracture-cavity reservoir.
FIG. 3 is a schematic diagram of a real fracture-cavity reservoir region in a specific experimental analysis.
FIG. 4 is a schematic diagram of a particular test analysis selecting a reservoir region for a simulation test.
FIG. 5 is a distribution plot of wells and karst tunnels for a particular experimental analysis of a selected reservoir region.
FIG. 6 is a graph of the pressure response of each well in a particular experimental analysis.
FIG. 7 is a graphical representation of amplitude magnitude and phase shift for each well in a particular experimental analysis.
FIG. 8 is a graphical illustration of amplitude magnitude and phase shift for each well within a selected zone in a particular experimental analysis.
Fig. 9 is a connection diagram of electronic components in the device for identifying karst pores of the fracture-cavity reservoir in the invention.
In the figure, 1-connecting rod, 2-piston plate, 3-pressure source well, 4-winding reel, 5-rope, 6-pulley, 7-pressure tester, 8-test well and 9-karst pore canal.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
For convenience of description, the following descriptive concepts are introduced in the present writing:
in the present invention, 'front', 'rear', 'left', 'right', 'up', 'down' all refer to the orientation in fig. 1, wherein 'front' refers to being out with respect to the paper in fig. 1 and 'rear' refers to being in fig. 1.
Referring to fig. 1, example 1: a device for identifying karst pore canals of a fracture-cavity type oil reservoir comprises a power device, a pressure generating device, a filtering device, a processor, a controller and a plurality of pressure testers 7.
The pressure generating device comprises a connecting rod 1 and a piston plate 2, the piston plate 2 is of a circular plate structure, the piston plate 2 is horizontally arranged, the connecting rod 1 is vertically arranged above the piston plate 2, the lower end of the connecting rod 1 is fixedly connected with the center of the piston plate 2, the piston plate 2 is arranged in a pressure source well 3, and the piston plate 2 is in sliding fit with the inner wall of the pressure source well 3.
The power device comprises a power source, a winding roll 4, a rope 5 and a pulley 6, wherein the pulley 6 is positioned above the winding roll 4 and the connecting rod 1, the winding roll 4 and the connecting rod 1 are respectively positioned at two sides of the pulley 6, one end of the rope 5 is fixed on the winding roll 4, the other end of the rope 5 upwards rounds the pulley 6 and is fixedly connected with the upper end of the connecting rod 1, and the power source is used for driving the winding roll 4 to rotate; in particular implementations, the power source may be an electric motor.
The testing ends of the plurality of pressure testers 7 are respectively positioned in a plurality of testing wells 8; the signal output ends of all the pressure testers 7 are respectively connected with the signal input end of the filter device, the signal output end of the filter device is connected with the signal receiving end of the processor, the signal output end of the processor is connected with the signal input end of the controller, and the control signal output end of the controller is connected with the power source.
Referring to fig. 1-9, example 2: a method for identifying karst tunnels of a fractured-vuggy reservoir is characterized in that a test area to be subjected to karst tunnel identification is determined in a fractured-vuggy reservoir area needing to be developed currently, a plurality of oil wells are arranged in the test area, any one of the plurality of oil wells in the test area is selected as a pressure source well 3, and a plurality of oil wells are selected as test wells 8 from the plurality of oil wells in the test area.
Calculating the amplitude response degree and the phase shift degree of each test well 8 in the test area by using the device for identifying the karst pores of the fractured-vuggy reservoir in the embodiment 1, and judging whether the test wells 8 are in the karst pore area according to the value intervals of the amplitude response degree and the phase shift degree of the test wells 8:
when the phase shift degree of the test well 8 is less than +100 degrees and the amplitude response degree is greater than 0, then the test well 8 and the pressure source well 3 have karst pores which are communicated with each other, which indicates that the area of the test well 8 is in the karst pore area.
When the phase shift degree of the test well 8 is greater than or equal to +100 degrees and the amplitude response degree is greater than 0, karst pores communicated with the pressure source well 3 are formed near the test well 8, and the area where the test well 8 is located is in the karst pore area.
When the amplitude response degree of the test well 8 is 0, there is no karst pore canal communicated with the pressure source well 3 between the test well 8 and the pressure source well 3, and there is no karst pore canal communicated with the pressure source well 3 near the test well 8, which indicates that the area where the test well 8 is located is not in the karst pore canal area.
Further, the amplitude response degree and the phase shift degree of each test well 8 are calculated as follows:
s110: and placing the pressure generating device into a pressure source well 3, and placing the testing ends of the plurality of pressure testers 7 into a plurality of testing wells 8 respectively.
S120: the processor sends periodic harmonic pressure signals to the controller, the controller controls the power source to drive the winding roll 4 to do circular reciprocating motion according to the periodic harmonic pressure signals, and the piston plate 2 does up-and-down periodic motion under the action of pulling force and self gravity, so that periodic harmonic pressure is generated in the pressure source well 3.
S130: each pressure tester 7 transmits a pressure signal corresponding to the pressure value in the test well 8 changing along with the time to the filter device, the filter device performs noise reduction processing on the pressure signal of each test well 8 according to the periodic harmonic pressure signal in S500, and then the filter device transmits the noise-reduced pressure signal of each test well 8 to the processor.
S140: the processor calculates the pressure signal of each test well 8 according to the periodic harmonic pressure signal in S120, and obtains the amplitude response degree and the phase shift degree of the pressure signal of each test well 8. The method for calculating the amplitude response degree and the phase shift degree of one pressure signal relative to the other pressure signal by calculating the known two pressure signals belongs to the prior art, and is not described herein again.
Further, the method for determining the value intervals of the phase shift degree and the amplitude response degree of the karst pore canal region of the test well 8 is as follows:
the method comprises the following steps of obtaining value intervals of phase shift degree and amplitude response degree for judging whether a test well 8 is in a karst pore passage area or not by simulating an underground periodic water pumping test, and specifically comprises the following steps:
s210: and obtaining a karst region schematic diagram and reservoir parameters of the N real fracture-cavity reservoirs, wherein the reservoir parameters comprise reservoir size, hydraulic conductivity of karst large channels, hydraulic conductivity of karst small channels, water storage coefficient of karst channels, matrix hydraulic conductivity and matrix water storage coefficient.
And S220, establishing a geological model of the fracture-cavity type oil reservoir for simulating the underground periodic pumping test of the karst region by taking the karst region schematic diagram of the real fracture-cavity type oil reservoir and the oil reservoir parameters as conditions.
And S230, setting a buffer area for simulating the underground periodic water pumping test.
S240, selecting a pressure injection point and a plurality of pressure test points from the geological model, and setting the period parameter and the amplitude parameter of the periodic flow signal of the pressure injection point, wherein the pressure injection point and the plurality of pressure test points respectively correspond to the oil wells in the karst region of the real fracture-cavity oil reservoir.
And S250, placing the geological model into a buffer area for simulation to perform an underground periodic water pumping test to obtain the amplitude response degree and the phase deviation degree of each test point.
And S260, analyzing the amplitude response degree and the phase shift degree of each test point, and comparing the amplitude response degree and the phase shift degree with the real condition whether the karst region of the real fracture-vug type oil reservoir is in the karst pore region to obtain a value interval for judging whether the test well 8 is in the phase shift degree and the amplitude response degree of the karst pore region.
S270, repeating the steps S220-S260 to obtain N value intervals for judging the phase deviation degree and the amplitude response degree of the karst pore canal region of the test well 8, eliminating the value intervals which obviously have calculation errors and are far larger or far smaller than the value intervals of the large part, averaging the rest value intervals to obtain the value intervals of the phase deviation degree and the amplitude response degree which are finally used for judging the karst pore canal region of the test well 8.
Further, the geological model comprises a control equation, an initial condition formula and a boundary condition formula, the control equation is shown as formulas (1-1) and (1-2),
in the formulas (1-1) and (1-2), i is an imaginary unit, ω represents the frequency of the pumping signal, SmatWater storage coefficient for the substrate, KmatIs the hydraulic conductivity of the matrix, gammaωFor phasors at a given frequency, QmRepresenting the amplitude, Q, of a periodic flow signalmRepresenting the amplitude of a periodic flow signal, (x-x)p) Is a Dirichlet distribution function, SkarIs the water storage coefficient of the karst pore canal,
is a tangent gradient operator in the karst pore canal, KkarIs the hydraulic conductivity of the karst pore canal.
The initial condition formula is shown as (2-1), the boundary condition formula is shown as (2-2),
γω(x,y)＝0(x,y)∈Ωboundary(2-2)，
in the equations (2-1) and (2-2), x represents the abscissa of the model, y represents the ordinate of the model, Ω represents the entire matrix and karst pore canal domain, and Ω representsboundaryRepresenting a domainA boundary.
Further, when the buffer is set in S230, an amplitude calculation formula, a phase offset calculation formula and buffer parameters are used, where the buffer parameters include a buffer size, a buffer hydraulic conductivity, and a buffer water storage coefficient.
The amplitude calculation formula is shown as (3-1), the phase shift calculation formula is shown as (3-2),
in equations (3-1) and (3-2), M represents the amplitude, x represents the abscissa of the model, y represents the ordinate of the model, Re represents the real part, γωFor the phasor at a given frequency, Im is the imaginary part,
indicating a phase shift.
In specific implementation, the derivation processes of the formulas (1-1), (1-2), (2-1) and (2-2) are as follows:
the periodic water pumping signal is shown as the formulas (4-1) and (4-2),
Q(t)＝-Qmcos(ωt) (4-1)，
in the equations (4-1) and (4-2), Q (t) represents a time-varying flow rate signal, QmRepresents the amplitude of the periodic flow signal, ω represents the frequency of the pumping signal, T represents time, and T represents the period of the pumping signal.
Substituting Darcy's equation into continuity equation to obtain partial differential equation of matrix and karst pore canal, as shown in equations (5-1) and (5-2),
in formulae (5-1) and (5-2), SmatIs the water storage coefficient of the matrix, h represents the water head, t represents the time, KmatFor the hydraulic conductivity of the matrix, Q (t) represents the flow signal as a function of time, (x-x)p) Is a Dirichlet distribution function, SkarIs the water storage coefficient of the karst pore canal,
is a tangent gradient operator in the karst pore canal, KkarIs the hydraulic conductivity of karst pores, xpIs a pumping coordinate.
The equations (5-1) and (5-2) are in the time domain, the initial conditions and the boundary conditions are as shown in the equations (6-1) and (6-2),
omega in the formulae (6-1) and (6-2) represents the entire matrix and karst pore space, omegaboundaryRepresenting the domain boundary.
Wherein the expression of the water head can be written as shown in equations (7-1) and (7-2),
h(x，y，t)＝hT(x，y，t) (7-1)，
hT(x，y，t)＝Re(γω(x，y)eiwt) (7-2)，
in the formulae (7-1) and (7-2), htRepresenting the periodic head, t representing time, Re being the real part, γωComplex number, phasor at a given frequency. e is a natural constant, i is an imaginary unit, and ω represents the frequency of the pumping signal.
By introducing complex numbers, the equations (5-1) and (5-2) can be rewritten as shown in (1-1) and (1-2),
in the formulae (1-1) and (1-2), i is an imaginary unit, SmatWater storage coefficient of matrix, gammaωFor phasors at a given frequency, KmatHydraulic conductivity of the matrix, QmRepresenting the amplitude of a periodic flow signal, (x-x)p) Which is the dirichlet distribution function, ω represents the frequency of the pumping signal,
is a tangent gradient operator in the karst pore canal, KkarIs the hydraulic conductivity of the karst pore canal.
In the frequency domain, the initial condition formula (6-1) and the boundary condition formula (6-2) are rewritten as shown in the formulas (2-1) and (2-2),
γω(x,y)＝0(x,y)∈Ωboundary(2-2)，
the formulas (3-1) and (3-2) are represented by the pair gammaωAnd performing exponential Fourier transform to obtain the target.
Specific test analysis:
and simulating an underground periodic water pumping test to obtain the amplitude response degree and the phase shift degree of each test well, so as to determine a value interval of the amplitude response degree and the phase shift degree for judging whether the test well is in a karst pore passage area.
In order to know the response of real fracture-cavity type oil reservoir matrix and karst pore canals to the periodic water pumping test, a part of real fracture-cavity type oil reservoir area is taken out in the test to carry out the simulated underground periodic water pumping test. Fig. 3 is a schematic diagram of karst areas of the tao-west kerr outcrops, and geological description shows that the outcrops ancient underground rivers, surface karsts and solution breakers in the outcrops are superposed and developed, are basically the same as the main reservoir types of the aodovicular fracture-vug type oil reservoirs in the tao-river oil fields, and can be used for simulating underground periodic water pumping tests.
Selecting the area shown in figure 4 and the corresponding oil reservoir parameters as raw data in a frame mode in figure 3 to carry out simulation test, selecting 11 oil wells in the area shown in figure 4, establishing a geological model shown in figure 5 according to figure 4 and the corresponding oil reservoir parameters, and showing the distribution conditions of the 11 oil wells and karst tunnels in figure 5, wherein the thick lines are large karst tunnels and the thin lines are small karst tunnels, the size of the geological model shown in figure 5 is 800m x 800m, the hydraulic conductivities of the karst large tunnels and the karst small tunnels are respectively 1m/s and 0.1m/s, and the water storage coefficients are both 1 x 10-8m-1The hydraulic conductivity of the matrix is 1 x 10-6m/s, water storage coefficient of 1 x 10-4m-1。
Encapsulating the geological model in a 1500m buffer with a hydraulic conductivity of 1 x 10-3m/s, water storage coefficient of 1 x 10-4m-1And the boundary condition is a constant pressure boundary, and the buffer area reduces the influence of the model boundary on the pressure propagation of the central region of the model.
Water pumping test with P7 as pressure injection point, T10 min, amplitude 0.04m3The periodic flow signal of/s is calculated to obtain the pressure response diagram of the 11 wells as shown in FIG. 6.
FIG. 7 is a graphical representation of amplitude magnitude and phase offset for each well, with P7 as the harmonic injection location and 10 minutes as the period, relative amplitude response in degrees and phase offset values in oscillatory responses within each well, the amplitude response in degrees and the phase offset in degrees, roughly divided into three degrees of connectivity by comparing the amplitude response in degrees and phase offset values within each well to the injected harmonic signal:
1) as can be seen from fig. 4 and 7, the karst tunnels communicating between P2, P3, P4, P7, P8, P9 and P11 and the harmonic injection position exist among P2, P3, P4, P7, P8, P9 and P11, which have the phase shift degree less than +100 ° and the amplitude response degree greater than 0.
2) It can be seen from fig. 7 that P5, P6, and P10 exist in which the degree of phase shift is +100 ° or more and the degree of amplitude response is greater than 0, and that there are no karst tunnels communicating with each other between P5, P6, and P10 and the harmonic injection position, but there are karst tunnels communicating with the harmonic injection position in the vicinity of P5, P6, and P10, and the main communication paths between P5, P6, and P10 and the harmonic injection position remain karst tunnels, and the lower the degree of communication between P5, P6, and P10 and the adjacent karst tunnels, the higher the phase shift value.
3) With the amplitude response level of 0, P1 is present, and it can be seen from fig. 7 that there is no karst tunnel interconnecting the harmonic injection location with P1, and there is no karst tunnel interconnecting the harmonic injection location near P1.
The working principle of the device for identifying the karst pore canal of the fracture-cavity type oil reservoir is as follows:
the processor sends periodic harmonic pressure signals to the controller, the controller controls the power source to drive the winding roll 4 to do circular reciprocating motion according to the periodic harmonic pressure signals, the winding roll 4 continuously withdraws and releases the rope 5, so that the piston plate 2 does vertical reciprocating motion under the action of upward tension and self gravity, when the piston plate 2 is positioned in the oil well, the piston plate 2 repeatedly extrudes the water in the oil well, so that the water in the oil well generates periodic harmonic pressure, the pressure testers 7 are used for collecting pressure signals in each oil well in a test area, the pressure testers 7 input the signals into the filter device for noise reduction treatment, then the filter device inputs the pressure signals into the processor, the processor calculates the pressure signals of each test well 8 according to the periodic harmonic pressure signals to obtain the amplitude response degree and the phase deviation degree of the pressure signals of each test well 8, thereby facilitating analysis of the condition of the karst tunnels of the test zone.
The process of the method for identifying the karst pore canal of the fracture-cavity type oil reservoir defined by the invention is as follows:
1. in a fracture-cavity type oil reservoir area needing to be developed currently, a test area for identifying karst pore canals is determined, a plurality of oil wells are arranged in the test area, any oil well is selected from the plurality of oil wells in the test area to serve as a pressure source well, and the plurality of oil wells are selected from the plurality of oil wells in the test area to serve as test wells.
2. The amplitude response degree and the phase shift degree of each test well in the test area are calculated by using the device for identifying the karst pores of the fractured-vuggy reservoir.
3. Judging whether the test well is in the karst pore canal region according to the value intervals of the amplitude response degree and the phase shift degree of the test well:
when the phase deviation degree of the test well is less than +100 degrees and the amplitude response degree is greater than 0, a karst pore canal which is communicated with each other is formed between the test well and the pressure source well, and the area where the test well is located is in the karst pore canal area;
when the phase deviation degree of the test well is more than or equal to +100 degrees and the amplitude response degree is more than 0, a karst pore canal communicated with the pressure source well is arranged near the test well, and the area where the test well is located is in the karst pore canal area;
when the amplitude response degree of the test well is 0, no karst pore canal which is communicated with the pressure source well exists between the test well and the pressure source well, and no karst pore canal which is communicated with the pressure source well exists nearby the test well, so that the area where the test well is located is not located in the karst pore canal area.
Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.
Claims (6)
1. The utility model provides a device for discerning fracture-cavity type oil reservoir karst pore, its characterized in that: comprises a power device, a pressure generating device, a filtering device, a processor, a controller and a plurality of pressure testers (7);
the pressure generating device comprises a connecting rod (1) and a piston plate (2);
the piston plate (2) is of a circular plate structure, the piston plate (2) is horizontally arranged, the connecting rod (1) is vertically arranged above the piston plate (2), the lower end of the connecting rod (1) is fixedly connected with the central position of the piston plate (2), the piston plate (2) is arranged in the pressure source well (3), and the piston plate (2) is in sliding fit with the inner wall of the pressure source well (3);
the power device comprises a power source, a winding roll (4), a rope (5) and a pulley (6);
the pulley (6) is positioned above the winding roll (4) and the connecting rod (1), the winding roll (4) and the connecting rod (1) are respectively positioned on two sides of the pulley (6), one end of the rope (5) is fixed on the winding roll (4), the other end of the rope (5) upwards bypasses the pulley (6) and is fixedly connected with the upper end of the connecting rod (1), and the power source is used for driving the winding roll (4) to rotate;
the testing ends of the pressure testers (7) are respectively positioned in the testing wells (8);
the signal output ends of all the pressure testers (7) are respectively connected with the signal input end of the filter device, the signal output end of the filter device is connected with the signal receiving end of the processor, the signal output end of the processor is connected with the signal input end of the controller, and the control signal output end of the controller is connected with the power source.
2. A method for identifying karst pores of a fracture-cavity type oil reservoir is characterized by comprising the following steps: in a fracture-cavity type oil reservoir area needing to be developed currently, determining a test area to be subjected to karst pore canal identification, wherein the test area is provided with a plurality of oil wells, any one oil well is selected from the plurality of oil wells in the test area to serve as a pressure source well (3), and the plurality of oil wells are selected from the plurality of oil wells in the test area to serve as test wells (8);
the device for identifying the karst pores of the fractured-vuggy reservoir is used for calculating the amplitude response degree and the phase shift degree of each test well (8) in the test area, and whether the test well (8) is in the karst pore area is judged according to the value interval of the amplitude response degree and the phase shift degree of the test well (8):
when the phase deviation degree of the test well (8) is less than +100 degrees and the amplitude response degree is greater than 0, the test well (8) and the pressure source well (3) are provided with karst pore passages which are communicated with each other, and the area where the test well (8) is located is in the karst pore passage area;
when the phase deviation degree of the test well (8) is more than or equal to +100 degrees and the amplitude response degree is more than 0, a karst pore canal communicated with the pressure source well (3) is arranged near the test well (8), and the area where the test well (8) is located is in the karst pore canal area;
when the amplitude response degree of the test well (8) is 0, no karst pore canal which is communicated with the pressure source well (3) exists between the test well (8) and the pressure source well (3), and no karst pore canal which is communicated with the pressure source well (3) exists near the test well (8), so that the area where the test well (8) is located is not located in the karst pore canal area.
3. The method for identifying karst tunnels for a fractured-vuggy reservoir of claim 2, wherein: the amplitude response degree and the phase deviation degree of each test well (8) are calculated by the following steps:
s110: placing the pressure generating device into a pressure source well (3), and placing the testing ends of the plurality of pressure testers (7) into a plurality of testing wells (8) respectively;
s120: the processor sends periodic harmonic pressure signals to the controller, the controller controls the power source to drive the winding roll (4) to do circular reciprocating motion according to the periodic harmonic pressure signals, and the piston plate (2) does up-and-down periodic motion under the action of pulling force and self gravity, so that periodic harmonic pressure is generated in the pressure source well (3);
s130: each pressure tester (7) transmits a pressure signal which corresponds to the pressure value in the test well (8) and changes along with time to a filter device, the filter device performs noise reduction processing on the pressure signal of each test well (8) according to the periodic harmonic pressure signal in S500, and then the filter device transmits the noise-reduced pressure signal of each test well (8) to a processor;
s140: and the processor calculates the pressure signal of each test well (8) according to the periodic harmonic pressure signal in S120 to obtain the amplitude response degree and the phase deviation degree of the pressure signal of each test well (8).
4. A method for identifying karst tunnels for a fractured-vuggy reservoir according to claim 2 or 3, wherein: the method for determining the value intervals of the phase shift degree and the amplitude response degree of judging whether the test well (8) is in the karst pore passage area comprises the following steps:
obtaining value intervals of phase shift degree and amplitude response degree for judging whether the test well (8) is in the karst pore passage area or not by simulating an underground periodic water pumping test, which is concretely as follows;
s210: obtaining a karst region schematic diagram and reservoir parameters of N real fracture-cavity reservoirs, wherein the reservoir parameters comprise reservoir size, hydraulic conductivity of karst large channels, hydraulic conductivity of karst small channels, water storage coefficient of karst channels, matrix hydraulic conductivity and matrix water storage coefficient;
s220, establishing a geological model of the fracture-cavity type oil reservoir for simulating the underground periodic pumping test of the karst region by taking the karst region schematic diagram of a real fracture-cavity type oil reservoir and oil reservoir parameters as conditions;
s230, setting a buffer area for simulating an underground periodic water pumping test;
s240, selecting a pressure injection point and a plurality of pressure test points from the geological model, and setting the period parameter and the amplitude parameter of the periodic flow signal of the pressure injection point, wherein the pressure injection point and the plurality of pressure test points respectively correspond to oil wells in the karst region of the real fracture-vug type oil reservoir;
s250, placing the geological model into a buffer area to simulate to carry out an underground periodic water pumping test to obtain the amplitude response degree and the phase deviation degree of each test point;
s260, analyzing the amplitude response degree and the phase shift degree of each test point, and comparing the amplitude response degree and the phase shift degree with the real condition whether the karst area of the real fracture-vug type oil reservoir is in the karst pore area to obtain a value interval for judging whether the test well (8) is in the phase shift degree and the amplitude response degree of the karst pore area;
s270, repeating the steps S220-S260 to obtain N value intervals for judging whether the test well (8) is in the phase deviation degree and the amplitude response degree of the karst pore canal region, eliminating the value intervals with obvious calculation errors in the N value intervals, and averaging the remaining value intervals to obtain the value intervals of the phase deviation degree and the amplitude response degree which are finally used for judging whether the test well (8) is in the karst pore canal region.
5. The method for identifying karst tunnels for a fractured-vuggy reservoir of claim 4, wherein: the geological model comprises a control equation, an initial condition formula and a boundary condition formula;
the control equation is shown in formulas (1-1) and (1-2);
in the formulas (1-1) and (1-2), i is an imaginary unit, ω represents the frequency of the pumping signal, SmatWater storage coefficient for the substrate, KmatIs the hydraulic conductivity of the matrix, gammaωFor phasors at a given frequency, QmRepresenting the amplitude, Q, of a periodic flow signalmRepresenting the amplitude of a periodic flow signal, (x-x)p) Is a Dirichlet distribution function, SkarIs the water storage coefficient of the karst pore canal,
is a tangent gradient operator in the karst pore canal, KkarIs the hydraulic conductivity of the karst pore canal;
the initial condition formula is shown as (2-1), and the boundary condition formula is shown as (2-2);
γω(x,y)＝0 (x,y)∈Ωboundary(2-2)；
in the equations (2-1) and (2-2), x represents the abscissa of the model, y represents the ordinate of the model, Ω represents the entire matrix and karst pore canal domain, and Ω representsboundaryRepresenting the domain boundary.
6. The method for identifying karst tunnels for a fractured-vuggy reservoir of claim 5, wherein: when the buffer area is set in the step S230, using an amplitude calculation formula, a phase offset calculation formula and buffer area parameters, where the buffer area parameters include a buffer area size, a buffer area hydraulic conductivity, and a buffer area water storage coefficient;
the amplitude calculation formula is shown as (3-1), and the phase offset calculation formula is shown as (3-2);
in equations (3-1) and (3-2), M represents the amplitude, x represents the abscissa of the model, y represents the ordinate of the model, Re represents the real part, γωFor the phasor at a given frequency, Im is the imaginary part,
indicating a phase shift.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010884819.4A CN111852457A (en) | 2020-08-28 | 2020-08-28 | Device and method for identifying karst pore passage of fracture-cavity type oil reservoir |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010884819.4A CN111852457A (en) | 2020-08-28 | 2020-08-28 | Device and method for identifying karst pore passage of fracture-cavity type oil reservoir |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111852457A true CN111852457A (en) | 2020-10-30 |
Family
ID=72967342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010884819.4A Withdrawn CN111852457A (en) | 2020-08-28 | 2020-08-28 | Device and method for identifying karst pore passage of fracture-cavity type oil reservoir |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111852457A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114109377A (en) * | 2021-11-29 | 2022-03-01 | 常州大学 | Experiment method for simulating well test of solution reservoir by ice burying and cave making |
-
2020
- 2020-08-28 CN CN202010884819.4A patent/CN111852457A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114109377A (en) * | 2021-11-29 | 2022-03-01 | 常州大学 | Experiment method for simulating well test of solution reservoir by ice burying and cave making |
| CN114109377B (en) * | 2021-11-29 | 2023-10-20 | 常州大学 | Experimental method for simulating broken solution reservoir well test by ice burying and cave building |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111581854B (en) | Oil reservoir state prediction method considering unbalanced anisotropic relative permeability | |
| CN104879103B (en) | A kind of seperated layer water injection effect analysis method | |
| CN106991236B (en) | Repeated fracturing well selection layer selection method based on four-dimensional ground stress dynamic change | |
| CN104750896B (en) | A kind of fractured-cavernous carbonate reservoir method for numerical simulation | |
| CN107066718B (en) | Four-dimensional dynamic ground stress simulation method | |
| AU2013397497B2 (en) | Static earth model calibration methods and systems using permeability testing | |
| CN106886058B (en) | The determination method and apparatus of compact oil reservoir effective reservoir physical property lower limit value | |
| CN104977617A (en) | Reservoir fracture identification method and imaging logging reservoir fracture identification method | |
| CN105089615A (en) | Log data historical retrogression treatment method based on oil reservoir model | |
| CN111060672B (en) | Method for reproducing whole history process of forming high-temperature overpressure natural gas reservoir | |
| NO20190291A1 (en) | Diffusion flux inclusion for a reservoir simulation for hydrocarbon recovery | |
| CN106154343A (en) | The method calculating the oil saturation of fine and close oil reservoir | |
| CN106501146B (en) | Method and device for determining physical upper limit of tight oil reservoir | |
| CN110532507B (en) | Method for improving drilling rate of compact oil reservoir of horizontal well | |
| Zangerl et al. | Consolidation settlements above deep tunnels in fractured crystalline rock: Part 2—Numerical analysis of the Gotthard highway tunnel case study | |
| CN111852457A (en) | Device and method for identifying karst pore passage of fracture-cavity type oil reservoir | |
| CN105626056A (en) | Method and device for determining three-dimensional stratum pore pressure of target area | |
| Izgec | Understanding waterflood performance with modern analytical techniques | |
| CN111997581B (en) | Heterogeneous oil reservoir development method and device and electronic equipment | |
| CN111155980B (en) | Water flow dominant channel identification method and device | |
| CN107219564A (en) | A kind of method and device for handling vertical even well profile | |
| CN116362121A (en) | Method and device for determining crack parameters of horizontal well fracturing | |
| CN105317432B (en) | A kind of same test method for depositing genesis mechanism of research spill and leakage | |
| Chen et al. | A boundary element model for falloff testing in unconventional reservoirs by considering natural fractures | |
| CN112502677B (en) | Water injection development effect evaluation method based on multiple linear regression |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20201030 |